Abstract: Subin Yoon
Mentor: Dr. Barber
There is great interest in the distribution and mobility of heavy metal contaminants in the Delaware River Estuary because it supplies drinking water to millions of people in the city of Philadelphia and Camden and also is home to many wildlife species, including some finfish and shellfish that are harvested for consumption. In this study I will be looking at geochemical relationship between the salinity gradient in the Delaware River Estuary and the concentration of heavy metals, particularly Pd and Cd, in tidal wetland sediments. This salinity gradient is displayed in the Delaware River Estuary by the tidal freshwater to the salt marshes. The salinity gradient can be divided into three major ecological zones. The freshwater zone extends from the head of the tide in Trenton, New Jersey downstream to Marcus hook, Pennsylvania and has an annual average salinity of 0.5 parts per thousand(ppt) or less. The saltiest zone extends from bay’s opening of the Atlantic Ocean, upstream to Artificial Island in New Jersey; salinity ranges from 35 to 18 ppt in this zone. Between these two zones the transitional mixing zone runs from Marcus Hook to Artificial Island and has salinities ranging from 0.5 to 18.0 ppt. With the increasing salinity gradient there is also change in ecology which is also important in the chemical mobility of heavy metals. This research of the Delaware Estuary is an extension of the study done by C.H. Darmstadlt in 1989 and Dawne E. ballard in 2002 which both looked at concentrations of Pd and Cd in Darby Creek and Tinicum Marsh which are part of the Delaware River Estuary. I will be using inductively coupled plasma mass spectrometry (ICP-MS) analysis to determine the Pb and Cd concentrations from the sampled sites.